1. Field of the Invention
The present invention relates to the dispensing of objects individually and particularly to the throwing of "clay pigeon" targets. More specifically, this invention is directed to apparatus for receiving and throwing plate type targets characterized by a catapult arm which is operated in such a manner as to minimize target breakage and which is partially automatically recocked subsequent to the throwing of each target. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
Apparatus for throwing "clay pigeon" plate type targets wherein the throwing or catapult arm is mechanically driven are well known in the art. In such apparatus the drive means, which actually imparts momentum to the throwing arm, is typically a powerful traction spring. The prior art apparatus thus generally comprises a throwing arm, designed to accomodate a frangible target plate, mounted on one end of a rotatable shaft. The other end of the rotatable shaft is mechanically coupled to a crank mechanism which, in turn, is connected to the traction spring. In operation the throwing arm must be moved to an angular position in which the spring is stretched, the arm must thereafter be released for the throwing stroke and then the arm is returned to the fully cocked position.
Various techniques and apparatus have previously been proposed to accomplish, against the force of the traction spring, the cocking of throwing arm of target plate throwing apparatus. Thus, by way of example, use has been made of compressed air jacks which, via a suitable transmission, pivot the rotatable shaft toward the arm cocked position after each throw. Systems employing compressed air jacks are expensive, complex and have a slow operational cycle. Accordingly, cocking devices for plate throwing apparatus which employ compressed air jacks or equivalent hydraulic means have not met wide acceptance and most prior art automatic plate throwing apparatus have employed motors which drive the rotatable shaft through reduction gearing.
The prior art motor driven devices for setting the throwing arms of target dispensing apparatus have also been characterized by certain difficulties and deficiencies. Thus, again by way of example only, the rotatable shaft to which the throwing arm is attached must be completely free for movement during the throwing stroke and thus the shaft can not be permanently driven. The apparatus must, accordingly, be provided with an angle pinion loosely mounted on the rotatable shaft; the angle pinion being connected by cooperating pinions to the reduction gearing on the drive motor output shaft. The angle pinion must, of course, be driven only through an arc, for the cocking of the throwing arm, and must be disconnected from the drive apparatus during the throwing stroke. Apparatus of the type described immediately above is complex, and thus comparatively expensive, and requires use of a powerful motor.
The target projecting arm, under the action of the traction spring, pivots at high speed during the throwing stroke and, because of the mass of and thus the inertia of the arm, moves beyond that angular position in which the spring is least stretched. Restated, at the end of the throwing stroke the traction spring tends to return the arm toward the cocked position producing oscillatory motion of the arm which results in considerable vibration. Such vibration or "bounce" can cause serious damage both to the throwing apparatus and to fragile targets positioned thereon or stored adjacent thereto. In an effort to overcome vibration of the throwing arm at the end of the throwing stroke it has been proposed to equip the rotatable shaft with a device which exerts a clamping effect in one direction only thus constraining the shaft to rotation in only one direction. These prior art vibration impeding devices, however, are characterized by the drive motor being constantly in rotation. This characteristic, in turn, requires that the throwing arm be locked in a cocked position and further requires that means be provided for disconnecting the motor output shaft from the remainder of the throwing arm drive apparatus. Thus, to enable a throwing operation, prior art devices with an arm vibration prevention feature have also had to include a throwing arm release mechanism.